Android Interview Questions

1. 1.What is android? Android is a stack of software for mobile devices which has Operating System, middleware and some key applications. The application executes within its own process and its own instance of Dalvik Virtual Machine. Many Virtual Machines run efficiently by a DVM device. DVM executes Java language byte code which later transforms into .dex format files, learn more what is android? 2.Describe a real time scenario where android can be used? Imagine a situation that you are in a country where no one understands the language you speak and you can not read or write. However, you have mobile phone with you. 3.How to select more than one option from list in android xml file? Give an example. Specify android id, layout height and width as depicted in the following example. 4.What languages does Android support for application development? Android applications are written using the Java programming language. 5.What is the Android Open Source Project? We use the phrase “Android Open Source Project” or “AOSP” to refer to the people, the processes, and the source code that make up Android. 6.What is the Guardian app for Android? The Guardian app for Android delivers all the best content from guardian.co.uk to your phone or tablet. Read the latest news, sport, comment and reviews, watch video, listen to brodcasts and browse stunning picture galleries while on the move. 7.What are the key components of Android Architecture? Android Architecture consists of 4 key components: - Linux Kernel - Libraries - Android Framework - Android Applications. 8.Where are lay out details placed? Why?

2. - Layout details are placed in XML files - XML-based layouts provide a consistent and standard means of setting GUI definition format. 9. What do containers hold? - Containers hold objects and widgets in a specified arrangement. - They can also hold labels, fields, buttons, or child containers. 9.What is Orientation? - Orientation decides if the LinearLayout should be presented in row wise or column wise fashion. - The values are set using setOrientation() - The values can be HORIZONTAL or VERTICAL 10.What is ADM? Mention at least three operation you can perform with ADB. ADB stands for Android Device Bridge, and is a command line tool developed to communicate with Android devices, whether they are an emulator or a physical device. There are many different operations we can perform with ADB: -Install or uninstall an application from the device -Pushing or pulling a file into or from the device -Access the Logcat of the device. Can you create Custom Views? How? To extend an Android View and create our own one, we need to create a class that inherits from the View class, and that has at least a constructor that receives an object Context and another one AttributeSet , as follows: class ExampleView extends View { public ExampleView (Context context, AttributeSet attrs) { super(context, attrs); } } If you want to create custom attributes for a custom View , you need to declare a <declare-styleable> resource element, and add it the custom attributes you need. How do I save the app to my SD card? A. From the device's Settings menu, go to Applications > Manage applications > The Guardian. Under the data

3. header, choose "Move to SD card" 11.What is Mono for Android? A. Mono for Android is a software development kit that allows developers to use the C# language to create mobile applications for Android-based devices.Mono for Android exposes two sets of APIs, the core .NET APIs that C# developers are familiar with as well as a C# binding to Android's native APIs exposed through the Mono.Android.* namespace. How to Become an Android Developer? 12.What do I need to develop Mono for Android applications? A.Mono for Android on Windows provides a plugin for Visual Studio 2010 Professional or better. We also support Mono for Android development using Mono Develop on Windows for users that do not own a copy of Visual Studio 2010 Professional or better.Mono for Android on Mac developers can use MonoDevelop.On all platforms, Mono for Android requires the Android SDK (which requires Java JDK) 13.Types of notification in android? Tost notification Status bar notification Dialog notification 14.What are the different storage methods in android? Android offers several different options for data persistence. Shared Preferences – Store private primitive data in key-value pairs. This sometimes gets limited as it offers only key value pairs. You cannot save your own java types. Internal Storage – Store private data on the device memory External Storage – Store public data on the shared external storage SQLite Databases – Store structured data in a private database. You can define many number of tables and can store data like other RDBMS. Architecture of Android 15.How would you print a message in the LOGACT and prevent the application to get started? static { System.out.println("Message"); System.exit(0); } This code will be executed before the application starts, and then the application will be killed before it has time to start

4. 16.How Would you upload multiple files to an HTTP SERVER in a single HTTP Request? Use MIME Multipart. It was thought to send different fragments of information in a single request, and is integrated with most of the native HTTP clients. 17.What are the key components of Android Architecture? Android Architecture consists of 4 key components: - Linux Kernel - Libraries - Android Framework 18.What is a Broadcast Receiver? Abroad Cast Receiver is a component that delivers a message system-wide, so any other component can capture it and interact with it. There are many of them provided from Android OS, such as broadcast to indicate a low level of battery, a disconnection of the WiFi or network or a screen that just turned on. However, custom Broad cast Receivers can also be defined in an application (and also declared in the AndroidManifest.xml) 19.Is There Any were to Implement Push Notifications in Android? Android supports natively push notifications with their Cloud Messaging (formerly Android Cloud to Device Framework). 20.What is it important to set permissions in app development? - Certain restrictions to protect data and code can be set using permissions. - In absence of these permissions, codes could get compromised causing defects in functionality. 21.What is SMP? Which Relation-Ship does it have with Android? SMP stands for Symmetric Multi-Processor. It describes an architecture for multiple processors accessing memory. Android was supporting a unique processor architecture until Android 3.0. Most of the Android devices have different cores, so it makes sense to make use of them (even if they are natively prepared to run applications only in one processor, and use the other ones for secondary tasks). Android provides a set of do and don’ts, such as not abusing volatile or synchronized variables. 22.What is Java HEAP? When a program starts, the JVM reserves some memory and uses this memory for all its need and part of this memory is call java heap memory. Heap in Java generally located at bottom of address space and move upward. When we want to create objects using the new operator, the object allocated memory from the Heap and when object dies or is garbage collected, the memory previously used goes back to Heap space in. 23.What are the advantages of having an emulator within the Android environment?

5. - The emulator allows the developers to work around an interface which acts as if it were an actual mobile device. - They can write, test and debug the code. - They are safe for testing the code in early design phase. 24.What is A View in Android? A View in Android is the most basic element to build a UI element. A View is contained in the package android.view.view. They occupy a rectangular area in the screen, and they capture interaction events with the view. They also render in the screen the content anytime it has been updated. 25.What is an Activity in Android? An Activity can be understood as a screen that performs a very particular action in an Android application (for example, we use an Activityto log in or to modify our profile). The activities interact with the user, they present a window and present an interactive UI inside (this is done through the function set Content View()). Activities are typically full-screen or also as a floating screen. They have their own cycle, and are pilled within a stack of Activities handle by the operative system. Know more about android technology through android online training at onlineitguru.com